System and methods for 3d model evaluation using triangle mesh hashing

A method for identifying deviations in an object, the method comprising:

• i) receiving first triangular mesh data describing an object at a first time;
• ii) evaluating at least one 3D triangle from the received triangular mesh data by (i) identifying one or more adjacent triangles using conditions for congruence of triangles;
• and (ii) performing neighbor facet edge hashing to produce an object hash value for each of the at least one 3D triangle;
• iii) creating a first 3D reference model comprises the respective object hash values for the at least one triangle of the first triangular mesh data;
• iv) receiving second triangular mesh data describing one of a similar object or the object at a second time that is subsequent to the first time;
• v) evaluating at least one 3D triangle from each received second triangular mesh data for each reference triangle:
• (a) identifying one or more adjacent triangles using conditions for congruence of triangles;
• (b) performing neighbor facet edge hashing to produce an object hash value for each of the at least one 3D triangle;
• (c) creating a second 3D reference model comprises the respective object hash values for the at least one triangle;
• and
• vi) comparing the first and the second 3D object models.